Today, when you want to subscribe to a calendar, you basically have two options:

Add the calendar's url to the list of external calendars in your calendar viewer.
You will receive updates, but won't be able to delete events you are not interested in.

Take a copy of the calendar and import it in your calendar viewer.
You will be able to delete events you are not interested in, but you won't receive any updates.

icalfilter.com lets you create filters for your imported ical (iCalendar, .ics) calendar feeds which you want to have updates from but hide events you are not interested in.
Good example uses are schedules, facebook events, etc.

Create

Just enter the url below and we will create a new url for you,
which you can add to the list of external calendars in your calendar viewer.
You will receive updates as usual but if you want to hide a event, all you have to do
is to click the link we add in the event description. You can also use the rule based advanced filter management.